Myself an some friends are currently working on a second year
undergraduate plant growth project. Our experiment is to test tolerance
levels to Zinc, in two familes (Gramineae & Leguminoseae). We have done
much research and have found out everything there is to know about
physiological uses of zinc, and ambient soil concentrations in typical
environments. What we cannot find is an upper limit for our zinc
concentrations. We have obviously limited resources, and plan to do 3
zinc concentrations with a control, and 4 replicates of each.
Can anyone tell us if they know an upper limit for zinc
concentration in the soil, that will kill almost all plant species.
Thanks in advance.